Tour Divide GPX is the route used for the annual event. It is NOT the official GDMBR ACA route, as described on the ACA maps. It includes several alternate sections not sanctioned by ACA but required by the TD event, including a route that skips Rawlins, WY, instead using the town of Wamsutter for resupply. Some of these alternates are described below. The route also follows two major, official ACA (paved) alternates (not TD-required, but de facto), intended for dodging inclement weather in New Mexico (Cuba to Grants and Grants to the Pie Town Road).

The 2017 v1 file is the most current for Tour Divide, and 2011 for the GDMBR.

GDMBR 2011 file is NOT completely current with 2016 ACA maps. It does not include the latest Butte routing, for example.

TD 2017 v1 update (5/31/17) - Added new TD-specific Fernie Alt. This alt is not recommended for a BoB trailer!

TD 2016 v2 update (5/20/16) - Added High Rockies Trail-North, west side of the Spray River

Unplug your GPS, turn it on and verify that the mapset is present (Setup|Map|Map Information Select Map), also pan/zoom to the route and verify you have topo lines and roads (you may have to zoom in significantly until full detail is shown).

With this GPS data and TopoFusion software you can see exactly where the route travels on topo maps and aerial photographs. With the time component and the "trip playback" feature you can see exactly how slow we were riding, where we stopped for lunch and even where we got lost!

Be aware that 140,000 point GPX files are slow to display on older systems, even using TopoFusion. It is recommended that you download the zip with each day as a separate file (Divide-AllDays-GPX.zip) to view the entire route at full detail.

GDMBR Waypoints

The detailed tracklogs available above are, unfortunately, too
detailed for today's GPS units. For use in the field, the GPS
waypoints available from Adventure Cycling are of more use. I used
these waypoints and routes to follow the GDMBR as we rode. These
points are the hard work of Fred Hiltz. Our tracklogs were used to
correct the Adventure Cycling waypoints since they did contain a
number of errors. Fred and I completed the updates to the waypoint
database in October '04.

The 10K GDMBR files provided above are an alternative to
the Adventure Cycling waypoints. Since all of the Adventure Cycling
waypoints/routes cannot be stored on (most of) today's units, this file provides the
advantage that in a single upload you can store the entire route (by uploading
the split point to the unit's saved tracks, or the entire file to the active
log). It is still detailed enough that looking at your position relative to
the track will give an good indication of whether you are following the route
or not. In fact, it can be more useful than the waypoints in some cases. Since
the waypoints are marked at junctions and turnoffs, the route that is formed by
connecting the waypoints often misses bends or switchbacks in the road. While
following the routes you are often well off the route, only to come back to it
at the next waypoint (see: TrekNow's
explanation).

Length and climbing on the GDMBR -- what does GPS have to say?

The route-only GDMBR.gpx file gives a total distance of 2476.21 miles,
which is only 13.8 miles short of what the Adventure Cycling maps
claim is the total distance of the route. This is actually a smaller
GPS error than I had anticipated. At the end of a day I often had
about a mile less on my GPS than what my cyclometer read. I have no
guarnatee that my cyclometer was calibrated correctly, however.
2005 update - I have since discovered that my cyclometer is indeed
over-estimating distance.

The total elevation gain along the route is still not certain. No one is willing to make a firm statement, however, 200,000 is the oft quoted figure. GDMBR.gpx claims 190,000 feet of climbing. My experience with GPS units, TopoFusion and various methods of computing the "total ascent" figure (See: Climbing Analysis) leads me to believe that the 190,000 figure is still an over-estimate. My guess is that the number is in the 160k to 170k rnage. 160,000 feet is still, without a doubt, a ridiculous amount of climbing--the equivalent of climbing from sea level to the top of Everest over 5 times!

The GPS data collected during our trip was used (with TopoFusion software) to
generate the profiles now used on the current ACA maps. The data corrected many gross errors on the '04 maps, and are considered a big improvement.

Data Collection details

To GPS the route I used a Garmin GPSMAP 60CS unit, mounted on my handlebars. I would have preferred a much smaller/lighter unit (Foretrex), since my primary purpose was to collect data, not navigate. But the battery life and tracklog capacity convinced me to take the larger unit. In the end the GPS did prove to be very useful for navigation, if only as confirmation that we were reading the map correctly. The 60CS also has the nice property that all of the mapsource topo maps fit on the unit. It cannot, however, store all of the waypoints and routes in the adventure cycling dataset.

It was quite a feat to successfully GPS our entire ride. It required me to bring a laptop computer (ugh), various cables, rechargeable batteries (and chargers). It's ridiculous that on a unit with 56mb of memory the tracklog is limited to 10,000 points. Even with today's units I should not have been forced to bring a laptop in order to download the data. How about 100,000 points, at least? Garmin, are you listening?

[Update 4/22/07] - The "X" series of Garmin units (e.g. Garmin Vista CX)
now has the capability to log GPS data to the data card on a daily basis. The
active log is still limited to 10,000 points, but it is now possible to collect
full data on a trip like the GDMBR without carrying a laptop. Super! One
caveat - there may be a bug or two. On a recent tour my batteries lost power
and though my active log was filled for the rest of that day, nothing made it
to the .gpx file on the data card for the day.

[Update 10/28/10] - Newer Garmin units (e.g. Oregon, Dakota, GPSMap 62) will
archive tracks and also can accept uploaded tracks of 10k and larger. There is
no need to split into 500 pt chunks anymore.

In the end I collected some 140,000 points along the route. The data was downloaded into TopoFusion software and saved into the GPX format. For the first half of the trip I collected data at 7 second intervals. This was due to a bug in the 60CS's AUTO mode that rendered it unusable. Mid trip I was able to update the firmware on my unit and begin using the AUTO mode.

Route only details

It was no small task to eliminate the backtracking, side trips and wrong turns that ran throughout the GPS data. After starting to process the data by hand I realized I was facing a bit too large of a task. It is very difficult to select points out by hand that represent points "off the route" -- especially when you are dealing with 140,000 of them. Side trips are usually not too much of a problem, but back tracking and spinning around in circles (or standstill points) are difficult both to spot and to eliminate correctly.

What I did instead was use the network algorithm to find the relevant points for me. I quickly realized that the network code cannot handle tracks that cross UTM zones, so after that fix I was able to crunch all of the data, then using the merge tool, recompose the route with all backtracking and side trips eliminated. Pretty slick, actually.

Uploading the 10k file

The 10,000 file is a great resource for GDMBR riders using a GPS. It shows the
entire route in very precise detail, allowing you to always verify if you are
"on-route" just by glancing down at the screen. For older Garmin GPS units
I recommend that you use the "split 500" file and upload the data into your "saved tracks" portion of
your track log memory. This leaves the active log free for data recording.

To do this, install TopoFusion, download the split file, and use File->Open on
it. Using the GPS transfer dialog, select "upload tracks" and "to Saved
Tracks." Make sure the split file is selected in the drop down, then hit begin.

In your track setup screen on the GPS, you should see 20 tracks, prefaced with
the letters A,B,C,D, etc, and the name GDMBR10K-split-500. You can verify the
data is there by selecting each saved track and viewing it on the map.